Let me second that by saying many of the systems in the Star Wars galaxy already have ingrained development that is static. For instance, Kuat will be nothing more than a Shipyard world for as long as it shall remain Kuat because it's culture and planetary infrastructure have reached its relative pinnacle of industrial development. The same can be said for virtually every other system in the galaxy.
Heavy Facilities can only produce Heavy Units. Light for Light. Every Capitol has a Basic Shipyard + Light Production Facilities so that you can at a minimum stock your capital ships and PDFs with something... but if you want the badass units you will have to go get them yourself.
You'll somewhat be in a unique position Ranes, since you'll get a factory ship of sorts to use, but count that as an exception to the rule.
When I post space platforms, there will be 1 platform that will be able to give a system a +1 SU boost, but that'll be it in terms of "building up" a system. (You can also bet that this platform WILL count against your PDF CP allotment and require some additional cash every Action Day to utilize).
NOTHING IS FREE IN THIS GAME!! =)